avcodec/mvha: Check remaining space when reading VLC table probabilities

Fixes: Infinite loop
Fixes: 19183/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MVHA_fuzzer-5666216765292544
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavcodec/mvha.c b/libavcodec/mvha.c
index 4b03a79283586e1cafa0405ee2e8fabfbd28467e..c270063b1c2db02dcd7e434a142d29c2d1f5b191 100644 (file)
--- a/libavcodec/mvha.c
+++ b/libavcodec/mvha.c
@@ -203,6 +203,9 @@ static int decode_frame(AVCodecContext *avctx,
         for (int i = 0; i < s->nb_symbols; symbol++) {
             int prob;
 
+            if (get_bits_left(gb) < 4)
+                return AVERROR_INVALIDDATA;
+
             if (get_bits1(gb)) {
                 prob = get_bits(gb, 12);
             } else {